Stannous Chloride → 6-Amino-7-bromo-1,4-dihydro-2,3-quinoxalinedione

HRID 439477Notes

Reaction equation

HRID 439477 reaction equation
[N+:1]([C:4]1[CH:5]=[C:6]2[C:11](=[CH:12][C:13]=1[Br:14])[NH:10][C:9](=[O:15])[C:8](=[O:16])[NH:7]2)([O-])=O.Cl[Sn]Cl>C(O)C.CS(C)=O>[NH2:1][C:4]1[CH:5]=[C:6]2[C:11](=[CH:12][C:13]=1[Br:14])[NH:10][C:9](=[O:15])[C:8](=[O:16])[NH:7]2

Participants

5

Reactant 2

HCID 24479Stannous ChlorideHCID 143915006-Bromo-7-nitro-1,4-dihydroquinoxaline-2,3-dione

Product 1

HCID 199586126-Amino-7-bromo-1,4-dihydro-2,3-quinoxalinedioneYield 67%

Reagents, catalysts & solvents 2

HCID 679Dimethyl SulfoxideSolventHCID 702EthanolSolvent

Conditions

Temperature
90 °C

Procedure

To a stirred mixture of 6-nitro-7-bromo-1,4-dihydro-2,3-quinoxalinedione (87 mg, 0.30 mMol) in ethanol (3 mL) and DMSO (0.5 mL) was added SnCl2 ·2H2O (343 mg, 1.50 mMol) in one portion. The mixture was refluxed at 80° C. (oil bath 90° C.) with stirring for 1 h to form a clear solution which was refluxed for another 1 h. It was then cooled to room temperature and the yellow precipitate was collected by filtration, followed by washing with cold ethanol (2×1 mL) to give 50 mg (67%) of crude title compound (contains minor impurities by NMR). Crystallization from DMSO/H2O gave 21 mg of pure as bright yellow needles, mp:>300° C. (dec. from 315° C.), changed color from 300° C. NMR (1H, DMSO-d6): d 5.257 (s, 2H); 6.558 (s, 1H); 7.087 (s, 1H); 11.599 (s, 1H); 11.792 (s, 1H). HRMS: calcd for C8H6N3O2Br (M+) m/z: 254.9642; found 254.9630. Potency relative to DCK: 7.1%.

Workup

  1. customto form a clear solution which
  2. temperaturewas refluxed for another 1 h
  3. temperatureIt was then cooled to room temperature
  4. filtrationthe yellow precipitate was collected by filtration
  5. washby washing with cold ethanol (2×1 mL)

Sources & evidence

ORD record
ord-ad861d7c9de54462a05571054811df8c
Source dataset
uspto-grants-1996_05
Patent number
US05514680

Reaction notes

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